300 likes | 774 Views
Qatar Liquified Gas Company Limited (II). QG2, the Designs and Technologies for a 7.8 MTPA Train March 10, 2009. Agenda. Overview Qatargas Site Overall Process Flow Key Technologies Conclusions. QG 2 On-Plots (By Development Phase). Trains 4 & 5 Process. Utilities. SW / CW.
E N D
Qatar Liquified Gas Company Limited (II) QG2, the Designs and Technologies for a 7.8 MTPA Train March 10, 2009
Agenda • Overview Qatargas Site • Overall Process Flow • Key Technologies • Conclusions
QG 2 On-Plots (By Development Phase) Trains 4 & 5 Process Utilities SW / CW Flares Inlet Facilities Slug Catcher
Qatargas Site Qatargas 2 Trains 4 & 5 (New) Qatargas Trains 1,2&3 (Existing)
Qatargas 2 - Overall Process Flow Scheme TRAIN 4 SULFUR RECOVERY SULFUR TO TRAIN 5 REFRIGERATION (C3, MR, N2) Chilled Selexol DEHYDRATION MERCAPTAN REMOVAL INLET FACILITY ACID GAS REMOVAL NGL RECOVERY LIQUEFACTION NITROGEN REJECTION OFFSHORE PRODUCTION LNG 07 FRACTIONATION C3, C4 TREATING PROPANE BUTANE PLANT CONDENSATE CONDENSATE TREATING FIELD CONDENSATE
Acid Gas Removal Unit • Design basis for Acid Gas Removal: • Feed gas flow rate ~ 1.5 Billion SCFD per train • H2S: 2.0% 2 ppmv • CO2: 3.6% 10 ppmv • COS: 1 ppmv • BASF aMDEA: • Single absorber possible • Lowest energy consumption • Low hydrocarbon co-absorption • Absorber size approaches limits for fabrication and handling • Vessel weight ~1450 tonnes • 6.8 m diameter, 188mm shell thickness
NGL Recovery Design to Make Lean LNG • Ortloff SCORE(*) Process • Provides > 99% recovery of propane. • Expander configuration: 3 x 50% machines to handle flow and provide sparing for high reliability • Lean Gas product is further recompressed before it enters the Liquefaction section • Deethanizer functions as “Scrub Column” in conventional LNG design • Higher mixed NGL recovery than with scrub column • (*) SCORE = Single Column Overhead Recycle
Liquefaction Process Size Step-Out • Evaluated train size increase using conventional liquefaction technologies • Joint study with Air Products considered: • Propane-Precooled Mixed Refrigerant Process • Dual Mixed Refrigerant • AP-X™ Hybrid Process • Selected AP-X™ Hybrid Process • Intensive technology qualification undertaken • Identified all process and equipment aspects that were outside current experience base • Developed and executed detailed qualifications to assess the new technologies • Gas turbine driver options • Large starter / helper / generator motors and variable frequency drives • Large refrigerant compressors • Nitrogen refrigeration circuit expander / compressors
AP-X™ Hybrid Process Overview FUEL Nitrogen Rejection LNG Expander / Compressor SUBCOOLER E C PROPANE COMPRESSORS PROPANE CHILLER & SMALL EXPANDER PRE-COOLING: PROPANE SYSTEM (Four Pressure Levels) NITROGEN COMPRESSOR COLD BOX SWEET GAS NGL RECOVERY DEHYDRATION NITROGEN REFRIGERATION MAIN HEAT EXCHANGER PROPANE-PLUS TO FRACTIONATION MIXED REFRIGERANT COMPRESSORS
Large Refrigeration Compressor Drivers • Identified GE Frame 9E as refrigerant compressor drives • Lower unit cost of power • 3000 rpm speed is ideal for compressor design • Allowed one Frame 9E per refrigerant string • Large starter/helper motors / generators • Required 45 MW (top at 60) • Large variable frequency drives • Dry Low NOx (DLN) technology • Waste heat used to generate high pressure steam to enhance plant thermal efficiency • Steam turbine generators • Steam turbine drivers • Process heat
Sulfur Recovery • Sulfur recovery regulations tightened at the time of QG2 approval to >99% • Recovery must be met across full span of possible H2S concentrations • Sulfur species removal includes H2S, COS and Mercaptans • High sulfur recovery met through application of proven technologies • H2S and COS removal using BASF-aMDEA (Lurgi) • Mercaptan removal by molecular sieves (UOP) • Molecular sieve regeneration gas treating by chilled Selexol process (UOP) • Sulfur Recovery Unit comprises: • Acid Gas Enrichment (ExxonMobil Flexsorb SE-Plus) • Claus Conversion (2-Stage Catalytic, with Lurgi Multi-Purpose Burner) • Tail Gas Treating (ExxonMobil Flexsorb SE-Plus)
Conclusions • QG2 onshore project has achieved a step function increase in LNG train liquefaction capacity through the use of new technologies • The application of new technologies has been made possible through extensive internal qualification processes working closely with vendors • The QG2 LNG plant will be the first application of the AP-X™ technology • First application of GE Frame 9 turbines in mechanical drive for LNG service and use of combined cycle cogeneration service to achieve a high thermally efficient LNG plant • The QG2 LNG plant is designed to meet very stringent environmental emissions standards for NOx and Sulfur recovery set forth by the state of Qatar